The present invention relates to a semiconductor integrated circuit device and, more particularly, to techniques that may be applied advantageously to one-chip microcomputers.
Some conventional one-chip microcomputers comprise an EPROM (erasable programmable read only memory) to which data processing and system control programs are written once by general-purpose program writer so as to shorten the development time schedule of each microcomputer. One such one-chip microcomputer is described illustratively in Japanese Patent Laid-open No. Sho 61-51659.
A plurality of kinds of microcomputers are provided with EPROM's of different storage capacities for use in diverse applications. From the assortment of these microcomputers, a user selects an appropriate microcomputer having an EPROM of the suitable storage capacity needed to accommodate processing programs addressing the system in which the microcomputer is to be incorporated.